<template>
  <div class="login_container">
    <!-- 头像区域 -->
    <div class="login_box">
      <div class="avatar_box">
        <img src="../assets/logo.png" alt="" />
      </div>

      <!--登录表单区域  -->
      <el-form ref="loginFormRef" :model="loginForm" :rules="loginFormRules" label-width="0px" class="login_form">
        <!-- 用户名 -->
        <el-form-item prop="username">
        <el-input v-model="loginForm.username" prefix-icon="iconfont icon-user" placeholder="请输入用户名"></el-input>
        </el-form-item>
        <!-- 密码 -->
        <el-form-item prop="password">
        <el-input v-model="loginForm.password" type="password" prefix-icon="iconfont icon-3702mima" placeholder="请输入密码"></el-input>
        </el-form-item>

        <!-- 按钮区域 -->
        <el-form-item class="btns">
          <el-button type="primary" @click="login">登录</el-button>
          <el-button type="info" @click="resetLoginForm">重置</el-button>
        </el-form-item>
      </el-form>
    </div>
  </div>
</template>

<script>
export default {
    data() {
        return {
            // 这是登录表单的数据绑定对象
            loginForm: {
                username: 'admin',
                password: '123456'
            },
            // 这是表单的验证规则对象
            loginFormRules: {
                // 验证用户名是否合法
                username: [
                    {required: true, message: '请输入用户名', trigger: "blur"},
                    {min: 3, max: 10, message: '用户名长度为3到10个字符', trigger: "blur"}

                ],
                // 验证密码是否合法
                password: [
                    {required: true, message: '请输入密码', trigger: "blur"},
                    {min: 6, max: 15, message: '密码长度为6到15个字符', trigger: "blur"}
                ]
            }
        };
    },
    methods: {
      // 点击重置按钮，重置登录表单
      resetLoginForm() {
        this.$refs.loginFormRef.resetFields();
      },
      login() {
        this.$refs.loginFormRef.validate(async valid => {
          if(!valid) return;
          const {data: res} = await this.$http.post('login', this.loginForm);
          if(res.meta.status !== 200) return this.$message.error('用户名或密码错误，登录失败！');
          this.$message.success('登录成功！');
          //1、将登录成功之后的token保存到客户端的 sessionStorage中
          // 1.1 项目中除了登录之外的其他API接口必须在登录之后才能访问
          // 1.2 token只应在当前网站打开期间生效，所以将token保存在sessionStorage中，而不是localStorage 中
          window.sessionStorage.setItem("token", res.data.token);
          //2、通过编程式导航跳转到后台主页，路由地址是 /home
          this.$router.push("/home");
        })
      }
    }
};
</script>

<style lang="less" scoped>
.login_container {
  background-color: #2b4b6b;
  height: 100%;
}
.login_box {
  width: 450px;
  height: 300px;
  background-color: #fff;
  border-radius: 3px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);

  .avatar_box {
    height: 130px;
    width: 130px;
    border: 1px solid #eee;
    border-radius: 50%;
    padding: 10px;
    box-shadow: 0 0 10px #ddd;
    position: absolute;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #fff;
    img {
      width: 100%;
      height: 100%;
      border-radius: 50%;
      background-color: #eee;
    }
  }
  .btns {
      display: flex;
      justify-content: flex-end;
  }
  .login_form {
     position: absolute;
     bottom: 0;
     width: 100%;
     padding: 0 20px;
     box-sizing: border-box;
  }
}
</style>
